Simplify the builder structure (#7)

* refactor: simplify builder\n\nfix some documentations, remove unecessary functions

* split in submodules

* format

lib/supabase/postgrest/behaviour.ex

@@ -0,0 +1,23 @@
+defmodule Supabase.PostgREST.Behaviour do
+  @moduledoc "Defines the interface for the main module Supabase.PostgREST"
+
+  alias Supabase.Client
+  alias Supabase.PostgREST.Builder
+  alias Supabase.PostgREST.Error
+
+  @type media_type ::
+          :json | :csv | :openapi | :geojson | :pgrst_plan | :pgrst_object | :pgrst_array
+
+  @callback with_custom_media_type(builder, media_type) :: builder
+            when builder: Builder.t() | Builder.t()
+  @callback from(Client.t(), relation :: String.t()) :: Builder.t()
+  @callback schema(Builder.t(), schema :: String.t()) :: Builder.t()
+
+  @callback execute(Builder.t() | Builder.t()) :: {:ok, term} | {:error, Error.t()}
+  @callback execute_string(Builder.t() | Builder.t()) ::
+              {:ok, binary} | {:error, Error.t() | atom}
+  @callback execute_to(Builder.t() | Builder.t(), atom) ::
+              {:ok, term} | {:error, Error.t() | atom}
+  @callback execute_to_finch_request(Builder.t() | Builder.t()) ::
+              Finch.Request.t()
+end

lib/supabase/postgrest/builder.ex

@@ -0,0 +1,79 @@
+defmodule Supabase.PostgREST.Builder do
+  @moduledoc """
+  Defines a struct to centralize and accumulate data to
+  be sent to the PostgREST server, parsed.
+  """
+
+  alias Supabase.Client
+
+  defstruct ~w[method body url headers params client schema]a
+
+  @type t :: %__MODULE__{
+          url: String.t(),
+          method: :get | :post | :put | :patch | :delete,
+          params: %{String.t() => String.t()},
+          headers: %{String.t() => String.t()},
+          body: map,
+          client: Supabase.Client.t(),
+          schema: String.t()
+        }
+
+  defp get_version do
+    :supabase_postgrest
+    |> :application.get_key(:vsn)
+    |> elem(1)
+    |> List.to_string()
+  end
+
+  @doc "Creates a new `#{__MODULE__}` instance"
+  def new(%Client{} = client, relation: relation) do
+    %__MODULE__{
+      schema: client.db.schema,
+      method: :get,
+      params: %{},
+      url:
+        URI.parse(client.conn.base_url)
+        |> URI.append_path("/rest/v1")
+        |> URI.append_path("/" <> relation),
+      headers: %{
+        "x-client-info" => "postgrest-ex/#{get_version()}",
+        "accept-profile" => client.db.schema,
+        "content-profile" => client.db.schema,
+        "content-type" => "application/json"
+      }
+    }
+  end
+
+  @doc """
+  Updates the key `#{__MODULE__}.params` and adds a new query params
+  """
+  def add_query_param(%__MODULE__{} = b, _, nil), do: b
+
+  def add_query_param(%__MODULE__{} = b, key, value) do
+    %{b | params: Map.put(b.params, key, value)}
+  end
+
+  @doc """
+  Updates the key `#{__MODULE__}.headers` and adds a new request header
+  """
+  def add_request_header(%__MODULE__{} = b, _, nil), do: b
+
+  def add_request_header(%__MODULE__{} = b, key, value) do
+    %{b | headers: Map.put(b.headers, key, value)}
+  end
+
+  @doc "Removes a request header"
+  def del_request_header(%__MODULE__{} = b, key) do
+    %{b | headers: Map.delete(b.headers, key)}
+  end
+
+  @doc "Changes the HTTP method that'll be used to execute the query"
+  def change_method(%__MODULE__{} = q, method) do
+    %{q | method: method}
+  end
+
+  @doc "Changes the request body that will be sent to the PostgREST server"
+  def change_body(%__MODULE__{} = q, body) do
+    %{q | body: body}
+  end
+end